Global ETD Search

111	Studie kalkulačního systému v inženýrské organizaci / The Study of Calculation System in Engineering Organization Műller, Tomáš January 2009 (has links) The goal of the submitted thesis is to analyse and improve current costing methods in a chosen engineering company. The theoretical part is devoted to definition of notions – cost types, segmentation of cost and then contains summary of costing technique and costing method. The theoretical analyse is centered on questions about costing in engineering company. The practical part describes company, his organization structure, processes and his productions. Further in the practical part is created analyse of current way costing of order and innovation suggestion. In the conclusion is cognisance evaluation from analyse of costing method and recommendation for the company.
112	Numerical simulation of acoustic wave propagation with a focus on modeling sediment layers and large domains Estensen, Elias January 2022 (has links) In this report, we study how finite differences can be used to simulate acoustic wave propagation originating from a point source in the ocean using the Helmholtz equation. How to model sediment layers and the vast size of the ocean is studied in particular. The finite differences are implemented with summation by parts operators with boundary conditions enforced with simultaneous approximation terms and projection. The numerical solver is combined with the WaveHoltz method to improve the performance. Sediment layers are handled with interface conditions and the domain is artificially expanded using absorbing layers. The absorbing layer is implemented with an alternative approach to the super-grid method where the domain expansion is accomplished by altering the wave speed rather than with coordinate transformations. To isolate these issues, other parameters such as variations in the ocean floor are neglected. With this simplification, cylindrical coordinates are used and the angular variation is assumed to be zero. This reduces the problem to a quasi-three-dimensional system. We study how the parameters of the alternative absorbing layer approach affect its quality. The numerical solver is verified on several test cases and appears to work according to theory. Finally, a semi-realistic simulation is carried out and the solution seems correct in this setting. Helmholtz wave equation acoustics ocean acoustics numerical analysis computational science finite differences summation by parts sbp waveholtz cylindrical coordinates sediment layers interface super-grid super grid absorbing layer Helmholtz vågekvationen akustik undervattensakustik numerisk analys beräkningsvetenskap finita differenser summation by parts sbp cylindriska koordinater waveholtz sedimentskikt interface super-grid absorberande lager Computational Mathematics Beräkningsmatematik
113	Auslegung von Mikrowellen-Thermoprozess-Anlagen unter Nutzung von hochfrequenz-technischen Prinzipien: am Beispiel eines Entbinderungsofens für keramische Grünkörper Reichmann, Markus 18 April 2011 (has links) Um der Mikrowellenerwärmung als Single- oder Hybridanwendung im industriellen Ofenbau ein weiteres Anwendungsspektrum zu eröffnen, wird dem Anlagenkonstrukteur im Rahmen dieser Arbeit eine Aufstellung von Entwicklungsprioritäten und Konstruktionshinweisen übergeben. Für eine energieeffiziente Ausnutzung des technologischen Potenzials wird hierbei nicht - wie in der Vergangenheit - die Feldstärkenverteilung, sondern das Reflexionsverhalten in den Vordergrund gestellt. Durch die Entwicklung und den Aufbau eines Messplatzes zur Bestimmung temperaturspezifischer Dielektrizitätsparameter konnte die Realitätsnähe der Simulation für die anwendungsorientierte Applikatorentwicklung gesteigert werden. Die Anwendbarkeit der Auslegungskriterien wird im Rahmen der Projektierung und des Aufbaus einer Beispielanlage zur Entbinderung von keramischen Grünkörpern und bei der Entwicklung zahlreicher mikrowellenspezifischer Anlagenbauteile verifiziert. info:eu-repo/classification/ddc/620 ddc:620 Mikrowellenerwärmung Entbinderung Grünling <Technik>
114	Characterizing optical and electrical properties of monolayer MoS2 by backside absorbing layer microscopy Ullberg, Nathan January 2020 (has links) Nanomaterials are playing an increasing role in novel technologies, and it is important to develop optical methods to characterize them in situ. To that end, backside absorbing layer microscopy (BALM) has emerged as a powerful tool, being capable to resolve sub-nanometer height profiles, with video-rate acquisition speeds and a suitable geometry to couple live experiments. In the internship, several techniques involving BALM were developed, and applied to study optical and electrical properties of the transition metal dichalcogenide (TMD) monolayer MoS2, a type of 2-dimensional (2D) crystalline semiconductor. A simulations toolkit was created in MATLAB to model BALM, a workflow to reliably extract linear intensities from the CMOS detector was realized, and 2D MoS2 was synthesized by chemical vapor deposition followed by transfer to appropriate substrates. BALM data of the 2D MoS2 was acquired and combined with simulations, giving a preliminary result for its complex refractive index at 5 optical wavelengths. In addition, the first steps towards coupling BALM with a gate biased 2D MoS2 field-effect transistor were explored. To complement BALM measurements, the grown samples were also characterized by conventional optical microscopy, scanning electron microscopy, atomic force microscopy, photoluminescence spectroscopy, and Raman spectroscopy. This work provides new additions to an existing platform of BALM techniques, enabling novel BALM experiments with nanomaterial systems. In particular, it introduces a new alternative for local extraction of optical parameters and for probing of electrical charging effects, both of which are vital in the research and development of nano-optoelectronics. backside absorbing layer microscopy BALM monolayer MoS2 TMD TMDC 2D materials nanomaterials nanotechnology refractive index extinction coefficient absorption coefficient field-effect transistor FET semiconductors optoelectronics optics raw image processing chemical vapor deposition CVD in situ characterization Nano Technology Nanoteknik Condensed Matter Physics Den kondenserade materiens fysik
115	In situ three-dimensional reconstruction of mouse heart sympathetic innervation by two-photon excitation fluorescence imaging Freeman, Kim Renee 25 February 2014 (has links) Indiana University-Purdue University Indianapolis (IUPUI) / The sympathetic nervous system strongly modulates the contractile and electrical function of the heart. The anatomical underpinnings that enable a spatially and temporally coordinated dissemination of sympathetic signals within the cardiac tissue are only incompletely characterized. In this work we took the first step of unraveling the in situ 3D microarchitecture of the cardiac sympathetic nervous system. Using a combination of two-photon excitation fluorescence microscopy and computer-assisted image analyses, we reconstructed the sympathetic network in a portion of the left ventricular epicardium from adult transgenic mice expressing a fluorescent reporter protein in all peripheral sympathetic neurons. The reconstruction revealed several organizational principles of the local sympathetic tree that synergize to enable a coordinated and efficient signal transfer to the target tissue. First, synaptic boutons are aligned with high density along much of axon-cell contacts. Second, axon segments are oriented parallel to the main, i.e., longitudinal, axes of their apposed cardiomyocytes, optimizing the frequency of transmitter release sites per axon/per cardiomyocyte. Third, the local network was partitioned into branched and/or looped sub-trees which extended both radially and tangentially through the image volume. Fourth, sub-trees arrange to not much overlap, giving rise to multiple annexed innervation domains of variable complexity and configuration. The sympathetic network in the epicardial border zone of a chronic myocardial infarction was observed to undergo substantive remodeling, which included almost complete loss of fibers at depths >10 µm from the surface, spatially heterogeneous gain of axons, irregularly shaped synaptic boutons, and formation of axonal plexuses composed of nested loops of variable length. In conclusion, we provide, to the best of our knowledge, the first in situ 3D reconstruction of the local cardiac sympathetic network in normal and injured mammalian myocardium. Mapping the sympathetic network connectivity will aid in elucidating its role in sympathetic signal transmisson and processing. Microscopy Multi-photon Two-Photon TPLSM Confocal GFP Sympathetic Nervous System Cardiac Neuron Heart Cardiomyocyte Fluorescence microscopy -- Research Multiphoton excitation microscopy Confocal microscopy Neurons Cellular signal transduction Muscle cells Myocardial infarction -- Research Myocardium Heart -- Pathophysiology Two-photon absorbing materials Heart -- Imaging Cardiovascular system -- Innervation Neuromuscular transmission Mice as laboratory animals -- Research
116	Analýza koaxiálních a jednovodičových nehomogenních struktur v časové oblasti / The Analysis of Coaxial and One-wire Non-homogeneous Structures in Time Domain Štverka, Dalibor January 2009 (has links) The work considers pulse wire-guided electromagnetic (EM) waves. The main contribution of the work is the original design of the isolation bushing for maximizing of the received wave (echo) thanks to the results of the numerical simulations, the acquirement of the new acknowledges of the reflections of the guided EM wave from the various boundaries, the construction of PML layers for FDTD simulations in rotational coordinates, the advances made in temporary excitation sources for FDTD and the formulation of the program code for FDTD in rotational coordinates in Matlab environment. The rightness of the numerical simulations was verified in practical experiments. The practical exploitation of the results is supposed in instrumentation and control technology - the level measurement in reservoirs.

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